Boiler wall and part thereof



T. .E. MURRAY JR 7 2,089,001 BOILER WALL AND PART THEREOF Filed March 2, 1936 INVENTOR. ZQOMAJEMREA JR fw M M ATTORNEYS Aug. 3, 1937;

Patented Aug. 3, 1937 nomtn wan. AND ran'r 'rnnnnor Thomas E. Murray,

Application March 2,

6- Claims.

In a certain prior patent, 1,746,711, dated February 11, 1930 there is described a hollow wall for boilers comprising upright tubes spaced apart and having fins extending over the intermediate spaces continuously from top to bottom. In the welding of such fins to the tubes, it has been found that internal stresses are produced which sometimes occasion breaks in the tubes when they are put to use under extreme high temperature conditions; and similar stresses in the fins which tend to cause oxidation at high temperatures.

In another Patent 2,029,437, Februaryd, 1936,

it is proposed to use a line of separate segments or projections instead of a continuous fin. The present invention is directed to improvements in the design of such separate projections. v The accompanying drawing illustrates embodiments of the invention. Fig. 1 is a horizontal section of a side wall of a boiler. Fig. 2 is an in-' side elevation of theupper portion of the same. Fig. 3 is an enlarged side elevation of one of the tubular units. Figs. 4, 5 and 6 are similarv-iews of modifications.

Referring to Fig. i, there is an outer 'wall structure of refractory bricks orblocks i and I a plastic insulating medium 2 and a retaining shell 3of sheet metal. Withinthis is a lining or wall of watertubes 4 spaced apart and provided with fin segments or projections designated as a wholeby the numeral 5. The upper ends of the upright tubes 4 may enter aheader 6 (Fig. 2) and their lower ends a similar header through which they are connected in any one of various com- 35 binations into the circulationof the boiler.

The-fin segments or projections 5 are spaced along each tube at diametrically opposite points and separately welded thereto so close to one another as to constitute an approximately or 40 substantially unbroken wall. The fin segments extend into the spaces between two adjacent tubes so as to practically cover the width of the space between them so that with the tubes they constitute a substantially unbroken metal wall ex- 45 posed to the heat within the furnace on one side,"

protecting the non-metallic outer portion of the wall from the fire and presenting an increased; heating surface (compared with plain tubes) for collecting and-conducting the heat to the water,

. to steam or mixture of the two within the tubes.

This causes a very rapid upward circulation and a considerable cooling eifect extending from the tubes through the segments.

According to this invention, the fin segmen 55 or projections are made of rods which are of mai- In, Brooklyn, N. Y. 1936, Serial No. 86,556

form section throughout their length, the crosssection being such as to present on the flre side of the wall a greater length than on the outer side.

In Fig.3 the desired distribution of. area of 5 the rods 5 is attained by making them in the shape of a triangle with a vertical back face 5 so that there are two frontfaces' 5 the total length of which is twice that of 5 The front and back areas bear the same relation, because 10 the rods are of uniform cross-section throughou't their length.

Fig. 4 illustrates a modification in which each of the projections has a straight rear face 5 and a half round convex face 5 of, naturally, in- 15 creased length.

v According to Fig. 5 the projections have vertical back faces 5 and a convex front face formed of converging flat faces 5 connected by a vertical portion 5*.

According to Fig. 6 the back faces of the projections are made hollow as at 5, and the front faces 5 are concentric therewith and of larger radius and consequently greater length.

In the several cases referred to the rods are of uniform cross-section throughout their length so that the front and back areas correspond to the lengths of the front and back portions of the perimeter of the cross-section.

-The-invention is useful chiefly in connection scribed is the most eflicient for absorbing radiant 5 heat per pound of metal in the projections. Such projections, therefore, are lighter than projections of the old style which were exposed to the radiant .heat on only half of their surface. or even less. It is a point of advantage to have the'tubular units'light, particularly in the common arrangement in which their weight is suspended from their upper ends. There is some advantage also in the cost of the metal, and in general it is preferable to use as light a structure as possible. u n v Various otherimodiflcations may be made by those skilled in the art without departing from I the invention as defined in the following claimsn What I claim is: g

1. A tubular unit of the character described adapted to-form a wall exposed on one side only to high temperatures, said unit comprising a tube for the heating and circulating of water or other fluid and having a series of separate projections PATENT o FFlcE on its exterior forming extended heating surfaces and being spaced so closely as to provide a substantially unbroken wall, said projections each comprising a metal rod of uniform cross-section throughout its length, which cross-section has a major portion of its perimeter on the fire side of the wall.

2. A tubular unit of the character described adapted to form a wall exposed on one side only to high temperatures, said unit comprising a tube for the heating and circulating of water or other fluid and having a series of separate projections on its exterior forming extended heating surfaces and being spaced so closely as to provide a substantially unbroken wall, said projections each said projections comprising a metal rod of umform cross-section throughout its length, which cross-section has a major portion of its perimeter on the fire side of the wall.

4. A wall construction for boilers'and the like comprising a wall exposed on one side only to the fire and comprising upright tubes connected into the circulation of the boiler, said tubes being spaced apart and having on their exterior separate projections extending into the spaces between them and spaced so closely as to form with the tubes a substantially unbroken wall, each of said projections comprising a metal rod of uniform cross-section throughout its length having a flat vertical out-er face and having a conve face on the side exposed to the fire;

5. A tubular unit oi the character described adapted to form a wall exposed on one side only to high temperatures, said unit comprising a tube for the heating and circulating of water or other fluid and having a series of separate projections on its exterior forming extended heating surfaces and being spaced so closely as to provide a substantially unbroken wall, said projections each comprising a metal rod of a cross-section which has a major portion of its perimeter on the fire side of the wall.

6. A wall construction for boilers and the like comprising a wall exposed on one side only to the fire and comprising upright tubes connected into the circulation of the boiler, said tubes being spaced apart .and having on their exterior separate projections extending into the spaces between them and spaced so closely as to form with the tubes a substantially unbroken well, each of said projections comprising a metal rod of a cross-section which has a major portion of its perimeter on the fire side of the wall.

THOMAS E. MURRAY, JR. 

